石油馏分中碱性氮含量测定的不确定度评估

Uncertainty Assessment for the Determination of Alkaline Nitrogen Content in Petroleum Fractions

使用电位滴定法测定了石油馏分中碱性氮的含量,详细分析了实验过程中影响碱性氮含量测量的各不确定度分量,具体包括标准滴定溶液浓度、测量重复性偏差、天平称重过程以及自动电位滴定仪引入的不确定度分量,研究计算这4个分量的具体不确定度数值并合成得到0.67%的总合成标准不确定度。取95%的置信概率,计算得到测定的石油馏分中碱性氮含量的扩展不确定度为1.35%,满足了碱性氮含量测定的不确定度要求。

The potentiometric titration method was used to determine the content of alkaline nitrogen in petroleum fractions.And various uncertainties affecting the measurement of alkaline nitrogen in petroleum fractions during the experiment were analyzed in detail,including the concentration of the standard titration solution,the measurement repeatability deviation,the weighing process of the balance and the automatic potentiometric titrator.The corresponding uncertainty values were calculated and finally the synthetic standard uncertainty was determined to be 0.67%.At the confidence probability of 95%,the extended uncertainty of 1.35%for the determination of alkaline nitrogen in petroleum fractions met the uncertainty requirement for the determination of alkaline nitrogen content.